题解 | 缺失的第一个正整数

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param nums int整型一维数组
     * @return int整型
     */
    public int minNumberDisappeared (int[] nums) {
        for (int i = 0; i < nums.length; i++) {
            int t = nums[i];
            while ( t <= nums.length && t - 1 >= 0 ) {
                int num = nums[t - 1];
                nums[t - 1] = t;
                nums[i] = num;
                t = nums[i];
                if (num >= nums.length || num < 1) {
                    break;
                }
                if (num == nums[num - 1]) {
                    break;
                }
            }
        }
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] != i + 1) {
                return i + 1;
            }
        }
        return nums.length + 1;
    }
}